Technical Field
The present invention relates to a light field image capturing apparatus, and in particular, to the enhancement of resolution of a light field image capturing apparatus that utilize the generation of Bessel-beam to enhance directional electric field distribution, uses proper focal lengths of micro-lenses to improve assembly permissible precision, uses geometric designed slit structures accompanied with different wavelength gains to produce circles of confusion for alignment, and obtains a relatively fine image by subsequently performing image capturing, analysis, calibration, and alignment.
Related Art
In the current light field image capturing apparatus, the technology of the light field image capturing apparatus is performed by using a single pinhole or a single micro-lens array; the image resolution is limited to the feature size of the pinhole or the micro-lens array; and the angular resolution and spatial resolution are trade-off to be effectively improved when the process feasibility is simultaneously taken into consideration.
For example, US patent reference (the U.S. Pat. No. 8,831,377 B2) discloses a light field image capturing method and apparatus, wherein a single micro-lens array is used to perform a multi-angle domain pixel information, usage of the single micro-lens array is limited due to an interference between the neighboring micro-lenses.
Further, for example, Chinese patent reference (the publication No. CN 101852676 B) discloses a method and an apparatus for measuring focal length by utilizing confocal configuration, wherein a single pinhole is mainly used to achieve super-long focal length based on a conjugate focal scanning architecture, so as to filter irrelevant spatial information, and a high-precision stepper motor is used to implement a multifocal plane precision scanning technology. However, when global scanning is performed by using the method and apparatus for multifocal differential focal length measurement, it is limited by precision and speed of the motor. The method and apparatus for multifocal differential focal length measurement cannot be used to perform quick global scanning, and cannot effectively represent advantages of resolution enhancement for light field image capturing apparatus.
Still further, for example, US patent reference (the publication No. US 20130108217 A1) discloses a micro-lens array and an optical transmission component, wherein the directional light field distribution is enhanced mainly by means of narrowing down an aperture to an optical fiber coupling apparatus. However, the performance of improving angular and spatial resolution is still trade-off.
In view of the above, it is necessary to provide a light field image capturing apparatus for effectively improving angular resolution and spatial resolution.